水煤浆气流床气化是目前大型先进煤气化技术之一，提升水煤浆气化效率有助于推动煤炭清洁高效利用。水煤浆预热技术被认为是提高煤气化能源利用效率的关键技术之一。目前，复杂液固悬浮液导热系数的变化规律和内在机理仍未被完全认识。导热系数是介质流动换热的重要基础参数，表征着其在稳态导热过程的导热能力。利用瞬态热线法测定不同温度下相同质量分数水煤浆的导热系数，实验结果表明：温度越高，导热系数越高。在室温下测定不同质量分数下水煤浆的导热系数，实验结果表明可以分为2个阶段：质量分数从51%增大到58%时为下降区，导热系数快速下降，由0.401 W/(m·K)降至0.358 W/(m·K)；而质量分数继续增加，从58%到67%时为恒定区，导热系数基本保持在0.358 W/(m·K)。基于实验结果，综合考虑平行模型、麦克斯韦模型、广义自洽模型等复合材料模型，提出煤颗粒−结合水复合的水煤浆导热系数平行预测模型。水煤浆中的水分包含自由水和结合水，结合水会和煤颗粒形成煤颗粒−结合水复合相，将水煤浆视为复合相和自由水相组成的两相复合材料。在下降区，随着煤颗粒质量分数的增加，自由水相减少，复合相不变，水煤浆导热系数快速降低；在恒定区，随着煤颗粒质量分数的进一步增加，复合相中的结合水量减少，但复合相的导热系数基本维持稳定。

Coal-water slurry gasification is one of advanced coal gasification technologies. The improvement on the efficiency of coal-water slurry gasification is helpful to promote the clean and efficient utilization of coal. Coal-water slurry preheating technology is considered as one of the key technologies to improve the energy utilization efficiency of coal gasification. At present, the variation pattern and intrinsic mechanism of thermal conductivity of complex liquid-solid suspensions are still not fully understood. The thermal conductivity is an important basic parameter of the medium flow heat transfer, characterizing its thermal conductivity in the steady-state thermal conductivity process. The transient hot wire method is used to measure the thermal conductivity of the same concentration coal-water slurry at different temperatures. The experimental results show that the higher the temperature, the higher the thermal conductivity. The thermal conductivity of coal-water slurry is determined at different mass concentrations with a room temperature. The experimental results show that it can be divided into two stages: the mass concentration increases from 51% to 58% in a drop zone, and the thermal conductivity decreases rapidly, its value decreases from 0.401 W/(m·K) to 0.358 W/(m·K); and the mass concentration continues to increase from 58% to 67% in a constant zone, and the thermal conductivity basically remains at 0.358 W/(m·K). Based on the experimental results, the parallel prediction model of thermal conductivity of coal-water slurry with coal particle-bonded water composite is proposed by considering the parallel model, Maxwell model, generalized self-consistent model and other composite models. The water in coal-water slurry contains free water and bound water, and the bound water will form a coal particle-bound water composite phase with coal particles, and the coal-water slurry is regarded as a two-phase composite composed of the composite phase and the free water phase. In the drop zone, with the increase of coal particle concentration, the free water phase decreases, the composite phase remains basically unchanged, and the thermal conductivity of coal-water slurry decreases rapidly. In the constant zone, the amount of bound water in the composite phase decreases with further increase in coal particle concentration, but the thermal conductivity of the composite phase remains basically stable. The model prediction results agree well with the experimental data.